Well today is the day, I got a P0304 last week. So today I'm replacing my left bank cylinder head. I'll post pics later this afternoon of tear down and install.

 

what was your made date?
also what kind of driving has the car seen before the failure?

 

4/12 is DOB, doesn't matter what kind of driving, faulty valve seat casting. Mine went at 13,500 miles, I've seen has far as 40k miles

 

Well the question to the driving is relevant, since we still dont know for sure, whether there are thermal issues with the exhaust port design in the head or simply use poor material.

Many guys that have the valve/seat issue report to have driven the car at higher highway speeds for prolonged periods of time just prior to the issue appearing. This would point to the poor design and also to the fact that no head revision to date has prooved to be a final cure (and it probably wont)...

 

My rig sees highway only on weekends and then it's for 15 miles maybe, normal is 10 miles a day 50-60mph with 6 lights in the mix.
I've changed out about a dozen heads without come backs and they're all 12's, no 13's to date, so I'd say something has been revised. And I've seen a least 30-40 heads replaced in my shop.

 

First 3 hours of work.

 

Maybe I'm missing the numbers here but if I'm correct you are changing a cylinder head on a 2012 model with only 13500 miles on it?!

If that's true, why the heck aren't you having the dealer do it? It says power train warranty all over it.

 

My guess is he works at the dealer from all the heads his shop has done

 

My left bank cylinder head started ticking at about 5k miles on my 2012. I haven't gotten the code yet. I am up to 15,500 miles and hope it spits the code soon. I don't want to have one head with 50k miles on it and one brand new.

 

Yes, I'm a dealer tech...lol